Blower and vacuum cleaner

ABSTRACT

A blower according to an exemplarily embodiment of the present disclosure includes a motor that includes a shaft disposed along a center axis extending vertically; an impeller that is connected to the shaft and rotates integrally with the shaft; an impeller housing that is disposed on an upper side of the impeller or a radially outer side of the impeller; a motor housing that is disposed on a radially outer side of the motor; a passage member that is disposed on a radially outer side of the motor housing with a gap interposed therebetween; and a plurality of stator blades that are arranged in a circumferential direction in the gap between the motor housing and the passage member. At least one of the stator blades includes a first stator blade disposed on either one of the motor housing and the passage member, and a second stator blade disposed on the other one of the motor housing and the passage member. The first stator blade and the second stator blade are coupled together in a radial direction or an axial direction.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a blower and a vacuum cleaner.

2. Description of the Related Art

Existing examples of a blower installed in a vacuum cleaner known thus far include multiple stator blades. Examples of such a blower include a blower disclosed in Japanese Unexamined Patent Application Publication No. 2002-138996. Japanese Unexamined Patent Application Publication No. 2002-138996 discloses an electric blower that includes splitter vanes around air passage exits formed between each pair of diffuser vanes on the outer circumference of a radial impeller, the splitter vanes having a smaller height than the diffuser vanes. This structure efficiently restores the airflow from the radial impeller using the diffuser by converting the dynamic pressure to the static pressure, and reduces the loss at a curved portion extending from the diffuser side to the return side. This structure can thus enhance the blowing efficiency.

SUMMARY OF THE INVENTION

However, in the electric blower disclosed in Japanese Unexamined Patent Application Publication No. 2002-138996, a fan casing is disposed while having a gap in the vertical direction between itself and the upper ends of the splitter vanes in the vertical direction. This structure thus fails to fix the splitter vanes and the fan casing to each other. This structure may also cause a turbulence in the gap between the fan casing and the upper ends of the splitter vanes in the vertical direction and may reduce the blowing efficiency of the electric blower.

A blower according to an exemplarily embodiment of the present disclosure includes a motor that includes a shaft disposed along a center axis extending vertically; an impeller that is connected to the shaft and rotates integrally with the shaft; an impeller housing that is disposed on an upper side of the impeller or a radially outer side of the impeller; a motor housing that is disposed on a radially outer side of the motor; a passage member that is disposed on a radially outer side of the motor housing with a gap interposed therebetween; and a plurality of stator blades that are arranged in a circumferential direction in the gap between the motor housing and the passage member. At least one of the stator blades includes a first stator blade disposed on either one of the motor housing and the passage member, and a second stator blade disposed on the other one of the motor housing and the passage member. The first stator blade and the second stator blade are coupled together in a radial direction or an axial direction.

The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a blower according to a first embodiment.

FIG. 2 is a perspective view of the blower according to the first embodiment.

FIG. 3 is a perspective view of a rotor assembly according to the first embodiment.

FIG. 4 is a front view of a bearing holding member according to the first embodiment.

FIG. 5 is an enlarged sectional view of a portion of the blower according to the first embodiment.

FIG. 6 is a sectional view of a blower according to a second embodiment, taken along line VI-VI in FIG. 8.

FIG. 7 is a perspective view of the blower according to the second embodiment.

FIG. 8 is a plan view of the blower according to the second embodiment.

FIG. 9 is a sectional view of a blower according to a third embodiment.

FIG. 10 is a perspective view of a motor housing according to the third embodiment.

FIG. 11 is a bottom view of a passage member according to the third embodiment.

FIG. 12 is a side view of a stator blade according to a fourth embodiment.

FIG. 13 is a side view of a stator blade according to a fifth embodiment.

FIG. 14 is a side view of a stator blade according to a sixth embodiment.

FIG. 15 is a perspective view of a vacuum cleaner according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinbelow, blowers according to embodiments of the present disclosure are described with reference to the drawings. The scope of the present disclosure is not limited to the following embodiments and are appropriately modifiable within the technical scope of the present disclosure. For ease of understanding, components in some drawings described below may be different from the actual ones in terms of, for example, scales or numbers.

The drawings appropriately illustrate a XYZ coordinate system as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z axis direction is parallel to the axial direction of the center axis J illustrated in FIG. 1. The Y axis direction is perpendicular to the Z axis direction, and the left-right direction in FIG. 1. The X axis direction is perpendicular to both Y axis direction and Z axis direction.

In the following description, the direction in which the center axis J extends (Z axis direction) is the vertical direction. The positive side of the Z axis direction (+Z side) is referred to as an “upper side (axially upper side)” and the negative side of the Z axis direction (−Z side) is referred to as a “lower side (axially lower side)”. The vertical direction, the upper side, and the lower side are simply used for description and do not limit the actual positional relationship or directions. Unless otherwise noted, the direction parallel to the center axis J (Z axis direction) is simply referred to as an “axial direction”, the radial direction from the center axis J are simply referred to as “a radial direction” and the circumferential direction around the center axis J is simply referred to as a “circumferential direction”.

As illustrated in FIG. 1 and FIG. 2, the blower 1 includes a motor 10, a bearing holding member 60, an impeller 70, a passage member 61, multiple stator blades 67, and an impeller housing 80. The bearing holding member 60 is attached to the upper side (+Z side) of the motor 10. The passage member 61 surrounds the radially outer side of the motor 10 in the circumferential direction. The impeller housing 80 is attached to the upper side of the passage member 61. The impeller 70 is housed between the bearing holding member 60 and the impeller housing 80 in the axial direction (Z axis direction). The impeller 70 is attached to the motor 10 so as to be rotatable around the center axis J. FIG. 2 does not include the illustrations of the passage member 61 and the impeller housing 80.

As illustrated in FIG. 1, the motor 10 includes a housing 20, a rotor 30, a stator 40, a lower bearing 52 a, an upper bearing 52 b, and a connector 90. The rotor 30 includes a shaft 31. In this embodiment, the upper bearing 52 b corresponds to a bearing. Thus, the blower 1 includes the rotor 30, the stator 40, the housing 20, the bearing, the bearing holding member 60, and the impeller 70. The lower bearing 52 a or both lower bearing 52 a and upper bearing 52 b may correspond to the bearing.

The housing 20 is cylindrical and open toward the upper side. The housing 20 houses the stator 40. The housing 20 houses the rotor 30. The housing 20 is, for example, a closed-bottomed cylindrical container. The housing 20 includes a cylindrical circumferential wall 21, a lower lid portion 22 located at the lower end of the circumferential wall 21, and a lower bearing holder 22 b located at a center portion of the lower lid portion 22. The stator 40 is fixed to the inner surface of the circumferential wall 21 of the housing 20. The lower bearing holder 22 b is cylindrical and protrudes to the lower side (−Z side) from the center portion of the lower lid portion 22. The lower bearing holder 22 b holds the lower bearing 52 a.

As illustrated in FIG. 1 and FIG. 2, the housing 20 has through holes 21 a. Each through hole 21 a extends from a lower portion of the circumferential wall 21 to the lower lid portion 22. Specifically, the through holes 21 a extend through the circumferential wall 21 in the radial direction and extend through the lower lid portion 22 in the axial direction (Z axis direction). Although not illustrated, for example, three through holes 21 a are provided to extend in the circumferential direction.

As illustrated in FIG. 1, the upper end portion of the through hole 21 a is located higher than the lower end portion of a stator core 41, described below. Thus, lower portion of the stator core 41 is exposed to the outside of the housing 20. The radially outer side of the stator core 41 thus faces an air-discharge passage 87, disposed between the motor 10 and a passage member 61. The air-discharge passage 87 is described below. This structure can cool the stator core 41 with air flowing through the air-discharge passage 87.

An example of a method for cooling the stator core 41 includes causing air to flow inside the housing 20. This method, however, causes a loss of air as a result of the components in the housing 20, such as the stator core 41 and coils 42, serving as a resistance that blocks air flow. This method thus has a problem of reducing the blowing efficiency of the blower 1.

In this embodiment, on the other hand, the outer surface of the stator core 41 is exposed to the air-discharge passage 87. Thus, the stator core 41 does not serve as a resistance of air flow inside the air-discharge passage 87. This embodiment can thus cool the stator core 41 without reducing the blowing efficiency.

The lower end portion of the through hole 21 a is located substantially the middle of the stator core 41 in the axial direction (Z axis direction). Specifically, in this embodiment, the lower half of the stator core 41 is exposed to the air-discharge passage 87. Thus, the stator core 41 is cooled more efficiently.

As illustrated in FIG. 1, the rotor 30 includes a shaft 31, rotor magnets 33, a lower magnet fastening member 32 a, and an upper magnet fastening member 32 b. The rotor magnets 33 are cylinders that surround the radially outer side of the shaft 31 around the axis (in the θz direction). The lower magnet fastening member 32 a and the upper magnet fastening member 32 b are cylindrical and have their outer diameters equivalent to that of the rotor magnets 33. The lower magnet fastening member 32 a and the upper magnet fastening member 32 b are attached to the shaft 31 while holding the rotor magnets 33 therebetween from both sides in the axial direction. The upper magnet fastening member 32 b includes a small-diameter portion 32 c at an upper portion in the axial direction (Z axis direction), the small-diameter portion 32 c having a smaller diameter than the portion on the lower side (closer to the rotor magnets 33).

The rotor 30 includes the shaft 31, disposed along the center axis J extending vertically (Z axis direction). The shaft 31 is supported by the lower bearing 52 a and the upper bearing 52 b so as to be rotatable around the axis (in the ±θz direction). Specifically, the bearings support the shaft 31 so that the shaft 31 is rotatable. The impeller 70 is attached to the shaft 31 at a portion above the bearing holding member 60. In FIG. 1, for example, the impeller 70 is attached to the upper (+Z) end portion of the shaft 31.

The stator 40 is located on the radially outer side of the rotor 30. The stator 40 surrounds the rotor 30 around the axis (in the θz direction). The stator 40 includes a stator core 41, an insulator 43, and coils 42.

The stator core 41 includes a core back portion 41 a and multiple (here, three) teeth 41 b. The core back portion 41 a is ring-shaped around the center axis. Each tooth 41 b extends from the inner circumferential surface of the core back portion 41 a toward the radially inner side. The teeth 41 b are equidistantly arranged in the circumferential direction.

The insulator 43 is attached to the teeth 41 b. The coils 42 are attached to the teeth 41 b with the insulator 43 interposed therebetween. Each coil 42 is a wound electric wire.

The lower bearing 52 a is held by the lower bearing holder 22 b with the elastic member 53 a interposed therebetween. The upper bearing 52 b is held by the holding cylinder 62 d with the elastic member 53 b interposed therebetween. The elastic members 53 a and 53 b can reduce the vibrations of the rotor 30.

The elastic members 53 a and 53 b are cylinders open toward both sides in the axial direction. The elastic members 53 a and 53 b are made of an elastic material. In this embodiment, the elastic members 53 a and 53 b may be made of, for example, a thermosetting elastomer (rubber) or a thermoplastic elastomer.

The elastic member 53 a is located on the inner side, in the radial direction, of the lower bearing holder 22 b. For example, the elastic member 53 a is fitted into a radially inner side of the lower bearing holder 22 b. The lower bearing 52 a is fitted into a radially inner side of the elastic member 53 a. The elastic member 53 b is located on the inner side, in the radial direction, of the holding cylinder 62 d. For example, the elastic member 53 b is fitted into the radially inner side of the holding cylinder 62 d. The upper bearing 52 b is fitted into a radially inner side of the elastic member 53 b.

The bearing holding member 60 is located at an upper opening of the housing 20. The bearing holding member 60 is cylindrical and surrounds and holds the upper bearing 52 b in the circumferential direction. As illustrated in FIG. 3, the bearing holding member 60 includes a holding member body 62 c, a first protrusion 62 a, and a second protrusion 62 b.

As illustrated in FIG. 1 and FIG. 2, the holding member body 62 c is, for example, a closed-top cylinder having the center axis J at the center. An upper lid portion of the holding member body 62 c has a hole through which the shaft 31 extends. As illustrated in FIG. 1, the holding member body 62 c is fitted to the inner side of the circumferential wall 21 of the housing 20. The bearing holding member 60 is thus fixed to the inner side of the housing 20.

As illustrated in FIG. 1 and FIG. 3, the holding member body 62 c includes an outer protrusion 63, which protrudes outward in the radial direction. Specifically, the bearing holding member 60 includes an outer protrusion 63. In FIG. 1 and FIG. 3, the outer protrusion 63 is annular to surround the center axis J. With the presence of the outer protrusion 63, the holding member body 62 c has, on its outer circumferential surface, a step at which the outer diameter of the holding member body 62 c increases from the lower side to the upper side. The undersurface of the outer protrusion 63 is in contact with the upper end surface of the housing 20. More specifically, the undersurface of the outer protrusion 63, that is, a stepped surface of the holding member body 62 c, perpendicular to the axial direction of the step, is in contact with the upper end surface of the housing 20, that is, the upper end portion of the circumferential wall 21. Thus, the holding member body 62 c (bearing holding member 60) has its position fixed in the axial direction.

As illustrated in FIG. 1, the holding member body 62 c includes a holding cylinder 62 d and an inner protrusion 64. Specifically, the bearing holding member 60 includes a holding cylinder 62 d and an inner protrusion 64. The holding cylinder 62 d is located at the center portion of the holding member body 62 c. The holding cylinder 62 d is a cylinder that is open at both ends in the axial direction and has the center axis J at the center. The holding cylinder 62 d is a cylinder that holds the upper bearing 52 b.

The inner protrusion 64 protrudes inward in the radial direction from the inner surface of the holding cylinder 62 d. In FIG. 1, the inner protrusion 64 protrudes from the upper end portion of the holding cylinder 62 d. As illustrated in FIG. 1 and FIG. 3, the upper surface of the inner protrusion 64 is located flush with the upper surface of the holding cylinder 62 d.

As illustrated in FIG. 1, the inner protrusion 64 faces at least part of the upper surface of the upper bearing 52 b in the axial direction. Thus, when the upper surface of the upper bearing 52 b is directly or indirectly brought into contact with the inner protrusion 64, the upper bearing 52 b can have its position fixed in the axial direction. In FIG. 1, the upper surface of the upper bearing 52 b is indirectly brought into contact with the inner protrusion 64 with the elastic member 53 b interposed therebetween.

The radially inner end of the inner protrusion 64 is located on the inner side, in the radial direction, of the radially outer end of the rotor 30. In other words, the distance in the radial direction from the center axis J to the radially outer end of the rotor 30 is larger than the distance in the radial direction from the center axis J to the radially inner end of the inner protrusion 64. Thus, the outer diameter of the rotor 30 can be easily increased and the motor 10 can increase the output. The radially outer end of the rotor 30 is, for example, the radially inner end of the rotor magnet 33.

The first protrusion 62 a protrudes upward from the upper surface of the holding member body 62 c. The first protrusion 62 a is annular to surround the center axis J in the circumferential direction. For example, the center axis J passes through the center of the first protrusion 62 a.

The second protrusion 62 b protrudes upward from the upper surface of the holding member body 62 c. Specifically, the first protrusion 62 a and the second protrusion 62 b protrude upward from the upper surface of the holding member body 62 c. The second protrusion 62 b is located on the outer side, in the radial direction, of the first protrusion 62 a. The second protrusion 62 b is annular to surround the center axis J and the first protrusion 62 a in the circumferential direction. For example, the center axis J passes through the center of the second protrusion 62 b. Specifically, the first protrusion 62 a and the second protrusion 62 b are annular to surround the center axis J.

In this embodiment, the bearing holding member 60 is constituted of multiple holding member pieces 60 a arranged in the circumferential direction. This structure enables an accurate adjustment of the balance of rotation of a rotor assembly 11, illustrated in FIG. 4. As illustrated in FIG. 4, the rotor assembly 11 is constituted of the impeller 70 fixed to the rotor 30 to which the upper bearing 52 b attached. Hereinbelow, the structure is described in detail.

The balance of rotation of the rotor assembly 11 is generally adjusted by separately adjusting the balance of the rotor 30 and the balance of the impeller 70. Thereafter, the motor 10 including the rotor 30 is assembled to fix the impeller 70 to the shaft 31 of the rotor 30. Here, due to assembly errors resulting from fixing the impeller 70 to the shaft 31, the balance of the rotor assembly 11 is adjusted again in the state where the impeller 70 is fixed to the shaft 31, that is, in the state of the rotor assembly 11. To date, the balance adjustment has been required multiple times to adjust the rotation balance of the rotor assembly 11, which takes time and trouble.

The balance of the rotor assembly 11 is adjusted by, for example, cutting off a portion of a component of the rotor assembly 11. Here, in the above-described existing method, the impeller 70 is attached to the shaft 31 after the motor 10 is assembled. In the state where the rotor assembly 11 is assembled, the rotor 30 is surrounded by the stator 40 and the housing 20. Thus, the balance of the rotor assembly 11 can be adjusted by only cutting off the impeller 70, not by cutting off part of the rotor 30. Specifically, the existing method allows the balance adjustment of the rotor assembly 11 only at one surface. This method fails to accurately adjust the rotation balance of the rotor assembly 11 depending on how the balance of the rotor assembly 11 is disturbed.

On the other hand, in this embodiment, the bearing holding member 60 is constituted of multiple holding member pieces 60 a. Thus, after the rotor assembly 11 illustrated in FIG. 4 is assembled, the rotor assembly 11 is inserted into the stator 40, and then the holding member pieces 60 a are assembled from the radially outer side of the upper bearing 52 b to assemble the motor 10. Thus, the balance of the rotor assembly 11 can be adjusted before the motor 10 is assembled. This structure enables adjustment of the balance by cutting off both the rotor 30 and the impeller 70. Specifically, the balance of the rotor assembly 11 can be adjusted at two or more surfaces. Thus, in this embodiment, the rotation balance of the rotor assembly 11 can be highly accurately adjusted.

Since the rotation balance of the rotor assembly 11 can thus be adjusted highly accurately, the balance of the rotor 30 and the impeller 70 does not need to be adjusted separately. Thus, the number of balance adjustment of the rotor assembly 11 can be reduced to one. This embodiment can thus reduce the time and trouble taken to adjust the rotation balance of the rotor assembly 11.

Since the bearing holding member 60 is constituted of multiple holding member pieces 60 a, the holding member pieces 60 a need to be kept in the assembled state. Here, in this embodiment, the bearing holding member 60 is fixed to the inner side of the housing 20. The holding member pieces 60 a can be combined together, for example, by fitting the bearing holding member 60 to the housing 20. In this case, the holding member pieces 60 a can be kept being combined together without being fixed using, for example, an adhesive. This structure thus requires less time and trouble to combine the holding member pieces 60 a together.

For example, as in this embodiment, in the case where the bearing holding member 60 is constituted of multiple holding member pieces 60 a, the holding member pieces 60 a are more likely to have dimensional errors and assembly errors. Thus, compared to the bearing holding member 60 constituted of a single component, the bearing holding member 60 is more likely to have large dimensional errors in the holding cylinder 62 d. Due to such dimensional errors, the holding cylinder 62 d may fail to stably hold the upper bearing 52 b.

On the other hand, according to this embodiment, the upper bearing 52 b is held by the holding cylinder 62 d with the elastic member 53 b interposed therebetween. This structure allows the elastic member 53 b to absorb dimensional errors of the holding cylinder 62 d, if included. According to this embodiment, the bearing holding member 60 constituted of multiple holding member pieces 60 a can also stably hold the upper bearing 52 b.

In the example of FIG. 3, the bearing holding member 60 includes three holding member pieces 60 a in combination. In this embodiment, the multiple holding member pieces 60 a have the same shape. Thus, the holding member pieces 60 a can be easily manufactured. For example, when the holding member pieces 60 a are manufactured by injection molding using a resin material, the holding member pieces 60 a can be manufactured using the same mold. Thus, the holding member pieces 60 a can be manufactured with less time, trouble, and costs. In the example of FIG. 3, the holding member pieces 60 a have a sector shape having a central angle of, for example, 120° when viewed in a plan.

As illustrated in FIG. 1, a connector 90 extends downward from the stator 40. The connector 90 protrudes to the lower side of the housing 20 through the through hole 21 a. The connector 90 includes a connection wire, not illustrated. The connection wire is electrically connected to the coils 42. When an external power source, not illustrated, is connected to the connector 90, power is supplied to the coils 42 through the connection wires.

The impeller 70 is fixed to the shaft 31. The impeller 70 is rotatable around the center axis J together with the shaft 31. The impeller 70 includes a base member 71, rotor blades 73, and a shroud 72. In this embodiment, the base member 71 is, for example, a single component. Specifically, the base member 71 is separate from the rotor blades 73. The base member 71 is made of, for example, a metal.

The base member 71 is a flat board extending in the radial direction. Specifically, the impeller 70 includes a flat base member 71 extending in the radial direction. The base member 71 faces the bearing holding member 60 in the axial direction with a gap interposed therebetween. Thus, the first protrusion 62 a, the second protrusion 62 b, and the base member 71 can form a labyrinth structure in the axial direction. More specifically, the first protrusion 62 a, the second protrusion 62 b, and a disc portion 71 a, described below, can form a labyrinth structure between the impeller 70 and the bearing holding member 60 in the axial direction (in the Z axis direction). This structure can thus prevent air from flowing into the gap between the impeller 70 and the bearing holding member 60. Thus, the blower 1 according to this embodiment can have high blowing efficiency.

The base member 71 includes a disc portion 71 a, an external cylinder 71 b, and an internal cylinder 71 c. Although not illustrated, the disc portion 71 a is a disc extending in the radial direction and has its center through which the center axis J passes. The external cylinder 71 b is a cylinder extending upward from the inner edge of the disc portion 71 a. The external cylinder 71 b has, for example, its center at the center axis J. The external cylinder 71 b has its upper end portion curved inward in the radial direction.

Thus, air that has flowed into the impeller 70 through an inlet port 80 a, described below, is more likely to flow outward in the radial direction along the upper surface of the external cylinder 71 b. Thus, according to this embodiment, the blower 1 can have high blowing efficiency.

The internal cylinder 71 c is located on the inner side, in the radial direction, of the external cylinder 71 b. The internal cylinder 71 c is a hollow cylinder extending in the axial direction (in the Z axis direction). The internal cylinder 71 c has, for example, its center at the center axis J. The internal cylinder 71 c has its upper end portion curved outward in the radial direction.

The upper end portion of the internal cylinder 71 c is smoothly continuous with the upper end portion of the external cylinder 71 b. A portion at which a portion of the internal cylinder 71 c above the disc portion 71 a is connected to the external cylinder 71 b forms a letter U shape, and is open to the lower side in a sectional view.

The shaft 31 is pressed into the radially inner side of the internal cylinder 71 c. Thus, the impeller 70 is fixed to the shaft 31. In the impeller 70 according to this embodiment, the shaft 31 is pressed into the radially inner side of the internal cylinder 71 c to fix the impeller 70 to the shaft 31 without using a separate fixing member. This structure can thus reduce the number of components of the blower 1. In addition, the disc portion 71 a, the external cylinder 71 b, and the internal cylinder 71 c are formed of a single component. This structure can further reduce the number of components of the blower 1. Thus, the number of assembly steps of the blower 1 can be reduced. Here, an example of the fixing member that is used to fix the impeller 70 to the shaft 31 is a nut.

When, for example, the shaft 31 is pressed into the cylinder extending in the axial direction from the inner edge of the disc portion 71 a, the stress is more likely to be localized at the connection portion between the disc portion 71 a and the cylinder. Thus, the impeller 70 may swing when receiving a stress from, for example, gyroscopic precession that occurs when the impeller 70 rotates.

On the other hand, in this embodiment, the shaft 31 is pressed into the internal cylinder 71 c located on the inner side, in the radial direction, of the external cylinder 71 b, which extends upward from the inner edge of the disc portion 71 a. This structure can thus prevent the stress from being localized at the connection portion between the disc portion 71 a and the external cylinder 71 b, and can enhance the solidity of a portion at which the disc portion 71 a, the external cylinder 71 b, and the internal cylinder 71 c are connected together. This structure can thus prevent the impeller 70 from swinging when the impeller 70 receives the stress.

The lower end portion of the internal cylinder 71 c is located lower than the disc portion 71 a. The lower end portion of the internal cylinder 71 c overlaps the bearing holding member 60 in the radial direction. The portion of the internal cylinder 71 c into which the shaft 31 is pressed is located lower than the disc portion 71 a. The lower end portion of the internal cylinder 71 c is in contact with the upper end portion of a shaft washer of the upper bearing 52 b.

Thus, the internal cylinder 71 c functions as a spacer that determines the position of the disc portion 71 a in the axial direction (in the Z axis direction). This embodiment can thus reduce the number of components of the blower 1 without the need for disposing a separate spacer and can further reduce the number of assembly steps of the blower 1.

Alternatively, for example, the following structure is conceivable: the internal cylinder 71 c extends upward beyond the external cylinder 71 b, and the portion of the internal cylinder 71 c into which the shaft 31 is pressed is located higher than the disc portion 71 a. In this case, however, the shaft 31 needs to have a large portion that protrude upward. This structure is thus disadvantageous in that the shaft 31 has a large dimension in the axial direction (in the Z axis direction).

In this embodiment, on the other hand, the internal cylinder 71 c extends downward below the disc portion 71 a. Thus, the portion of the internal cylinder 71 c into which the shaft 31 is pressed can be located below the disc portion 71 a, so that the shaft 31 can have a smaller dimension in the axial direction (in the Z axis direction).

The method for manufacturing the base member 71 is not limited to a particular one. In this embodiment, the base member 71 is a single component made of metal and including the disc portion 71 a, the external cylinder 71 b, and the internal cylinder 71. For example, the base member 71 can be manufactured by, for example, performing burring on a metal plate. The impeller 70 can be easily manufactured with this method. When the base member 71 is manufactured from a plate, the base member 71 can have a lighter weight than in the case where the base member 71 is manufactured by, for example, die casting.

The rotor blades 73 are located on the upper surface of the disc portion 71 a. The rotor blades 73 are inserted into, for example, grooves in the upper surface of the disc portion 71 a and fixed to the upper surface of the disc portion 71 a. The multiple rotor blades 73 are arranged in the circumferential direction.

The shroud 72 is an annular portion facing the upper surface of the disc portion 71 a. The inner edge of the shroud 72 is concentric with, for example, the disc portion 71 a. The shroud 72 is fixed to the disc portion 71 a with the rotor blades 73 interposed therebetween.

As illustrated in FIG. 2, the shroud 72 includes a shroud annular portion 72 a and a shroud cylinder portion 72 b. The shroud annular portion 72 a is an annular plate. The shroud cylinder portion 72 b is a cylinder extending upward from the inner edge of the shroud annular portion 72 a. The shroud cylinder portion 72 b includes an impeller opening 72 c that is open to the upper side. The shroud cylinder portion 72 b is located on the outer side, in the radial direction, of the external cylinder 71 b of the base member 71.

As illustrated in FIG. 5, the inner surface of the shroud cylinder portion 72 b includes a curved surface 72 d. The curved surface 72 d is located at the upper end portion of the inner surface of the shroud cylinder portion 72 b. The curved surface 72 d is curved outward in the radial direction from the lower side toward the upper side.

An impeller passage 86 is disposed between the shroud annular portion 72 a and the disc portion 71 a in the axial direction (in the Z axis direction). The impeller passage 86 is partitioned by the multiple rotor blades 73. The impeller passage 86 is connected to the impeller opening 72 c. The impeller passage 86 is open to the radially outer side of the impeller 70.

The impeller 70 has its position fixed in the axial direction by the internal cylinder 71 c, functioning as a spacer. The undersurface of the impeller 70, that is, the undersurface of the disc portion 71 a is located adjacent to the upper end of the first protrusion 62 a of the bearing holding member 60 and the upper end of the second protrusion 62 b of the bearing holding member 60. Thus, the above-described labyrinth structure is formed. This structure can prevent air discharged from the impeller passage 86 of the impeller 70 to the radially outer side from flowing from the outer side toward the radially inner side through the gap between the impeller 70 and the bearing holding member 60. The blower 1 according to this embodiment can thus have a higher blowing efficiency.

As illustrated in FIG. 1, the passage member 61 is a cylinder that surrounds the radially outer side of the motor 10. The passage member 61 has an inner diameter that decreases downward from the upper end portion and increases toward the lower side from the portion having the minimum inner diameter. In other words, a passage member inner surface 61 c of the passage member 61, which is a radially inner surface, is located further to the radially inner side from the upper end portion toward the lower side, and then located further to the radially outer side toward the lower side from the radially innermost position

The passage member 61 has a maximum inner diameter at, for example, the upper end portion. In other words, the passage member inner surface 61 c is located, for example, at the outermost in the radial direction in the upper end portion.

An air-discharge passage 87 extending in the axial direction (in the Z axis direction) is disposed between the passage member 61 and the motor 10 in the radial direction. Specifically, the passage member 61 and the motor 10 define the air-discharge passage 87. The air-discharge passage 87 extends around in the circumferential direction. In this embodiment, the outer surface of the motor 10, that is, the outer circumferential surface of the housing 20 is a cylinder that extends linearly in the axial direction. Thus, the air-discharge passage 87 has its radial width changed in accordance with the inner diameter of the passage member 61.

Specifically, the radial width of the air-discharge passage 87 decreases from the upper end portion toward the lower side, and then increases toward the lower side from the minimum width portion. The air-discharge passage 87 has a maximum radial width at, for example, the upper end portion. When the air-discharge passage 87 has its width changed in this manner, the air flowing through the air-discharge passage 87 can have a higher static pressure. This structure can thus prevent the air flowing through the air-discharge passage 87 from flowing in the reverse direction, that is, from flowing from the lower side to the upper side.

As the radial width of the air-discharge passage 87 decreases, the air-discharge passage 87 has its position located further to the radially inner side, and as the radial width of the air-discharge passage 87 increases, the air-discharge passage 87 has its position located further to the radially outer side. Here, as the air-discharge passage 87 is located further to the radially inner side, the air-discharge passage 87 has a smaller dimension in the circumferential direction, so that the passage area of the air-discharge passage 87 decreases accordingly. On the other hand, as the air-discharge passage 87 is located further to the radially outer side, the air-discharge passage 87 has a larger dimension in the circumferential direction, so that the passage area of the air-discharge passage 87 increases accordingly.

For example, when the air-discharge passage 87 having a small radial width has its position located on the outer side in the radial direction, the air-discharge passage 87 has a passage area not sufficiently small, so that the air passing through the air-discharge passage 87 is less likely to have a high static pressure.

In this embodiment, on the other hand, the air-discharge passage 87 is located further to the radially inner side as the air-discharge passage 87 has a smaller radial width. Thus, the air-discharge passage 87 can have a sufficiently small passage area by reducing the radial width. On the other hand, the air-discharge passage 87 can have a sufficiently large passage area by increasing the radial width. The air-discharge passage 87 can have widely different passage areas, so that the air passing through the air-discharge passage 87 can have a high static pressure. Thus, this embodiment can prevent air flowing through the air-discharge passage 87 from flowing in the reverse direction.

Herein, the position of the air-discharge passage in the radial direction includes the position of the radially outer end of the air-discharge passage in the radial direction.

An outlet port 88 is disposed at the lower end portion of the air-discharge passage 87. The outlet port 88 is a portion for discharging air that has flowed into the blower 1 from an inlet port 80 a, described below. In this embodiment, the position of the outlet port 88 in the axial direction is substantially the same as the position of the lower end portion of the motor 10 in the axial direction.

In this embodiment, the passage member 61 includes an upper passage member 61 b and a lower passage member 61 a. The upper passage member 61 b is connected to the upper side of the lower passage member 61 a. The upper passage member 61 b has an inner diameter that decreases from the upper end portion toward the lower side. The lower passage member 61 a has an inner diameter that increases from the upper end portion toward the lower side. Specifically, the portion of the passage member 61 having the minimum inner diameter is located at the same position in the axial direction (Z axis direction) as a coupling position P1, at which the upper passage member 61 b and the lower passage member 61 a are coupled together. Similarly, the portion of the air-discharge passage 87 having the minimum radial width is located at the same position in the axial direction as the coupling position P1.

The blower 1 includes multiple stator blades 67. The multiple stator blades 67 are fixed to the outer surface of the bearing holding member 60. The holding member pieces 60 a and the stator blades 67 may be integrated together. The multiple stator blades 67 are disposed between the passage member 61 and the motor 10 in the radial direction. Specifically, the stator blades 67 are disposed inside the air-discharge passage 87. The stator blades 67 reorient the air flowing in the air-discharge passage 87. As illustrated in FIG. 2, the multiple stator blades 67 are equidistantly arranged in the circumferential direction. Each stator blade 67 includes a stator blade lower portion 67 a and a stator blade upper portion 67 b. The stator blade lower portion 67 a extends in the axial direction (in the Z axis direction).

The stator blade upper portion 67 b is connected to the upper end portion of the stator blade lower portion 67 a. The stator blade upper portion 67 b is curved clockwise (−θ_(Z) direction), when viewed in a plan, from the lower side toward the upper side.

As illustrated in FIG. 1, the stator blade lower portions 67 a overlap with, for example, the lower passage member 61 a in the radial direction. The stator blade upper portions 67 b overlap with, for example, the upper passage member 61 b in the radial direction. In this embodiment, each stator blade lower portions 67 a and the corresponding stator blade upper portion 67 b are, for example, parts of a single component. In this embodiment, each stator blade 67 is manufactured as, for example, a single component integrated with the upper passage member 61 b.

The impeller housing 80 is a cylindrical member. The impeller housing 80 is attached to the upper end portion of the passage member 61. The impeller housing 80 includes an inlet port 80 a that is open to the upper side.

The impeller housing 80 includes an impeller housing body 82 and an inlet guide 81. The impeller housing body 82 is a cylinder that surrounds the radially outer side of the impeller 70 and is open to both sides in the axial direction. The upper end portion of the passage member 61 is fitted to the radially inner side of the impeller housing body 82. In this embodiment, the upper end portion of the passage member 61 is, for example, pressed into the radially inner side of the impeller housing body 82.

As illustrated in FIG. 5, the impeller housing body 82 has, at the lower end portion, a step 83 at which the inner diameter of the impeller housing body 82 increases from the upper side toward the lower side. The upper end surface of the passage member is in contact with a step surface 83 a of the step 83 that extends perpendicular to the axial direction. Thus, the impeller housing body 82 has its position fixed in the axial direction (in the Z axis direction) with respect to the passage member 61.

The inner surface of the impeller housing body 82 has a curved surface 82 a and a shroud-facing surface 82 b. The curved surface 82 a is a curved surface having an arc-shaped cross section and located further to the radially outer side from the upper side to the lower side. The curved surface 82 a is steplessly continuous with the passage member inner surface 61 c. Thus, the air flowing over the curved surface 82 a is less likely to cause a loss when flowing into the air-discharge passage 87. Thus, the blower 1 according to this embodiment can have high blowing efficiency.

The curved surface 82 a faces a radially outer opening of the impeller 70 in the radial direction. A connection passage 84, which connects the impeller passage 86 and the air-discharge passage 87 to each other, is disposed between the curved surface 82 a and the impeller 70 in the radial direction.

The radial width of the connection passage 84 increases from the upper side toward the lower side. Specifically, the connection passage 84 has a maximum radial width at the lower end portion. The lower end portion of the connection passage 84 is a portion connected to the upper end portion of the air-discharge passage 87. The radial width of the lower end portion of the connection passage 84 and the radial width of the upper end portion of the air-discharge passage 87 are the same.

As described above, the air-discharge passage 87 has, at its upper portion, its width decreasing from the upper side toward the lower side. Thus, in the passage from the connection passage to the upper portion of the air-discharge passage 87, the passage width is maximum at a portion at which the connection passage 84 and the air-discharge passage 87 are connected together. In other words, at the portion having the maximum width in the passage from the connection passage 84 to the upper portion of the air-discharge passage 87, the step 83, which is a connection portion between the impeller housing 80 and the passage member 61, is disposed.

The upper end portion P2 of the curved surface 82 a is located higher than the radially outer end portion of the undersurface of the shroud annular portion 72 a. Thus, air discharged from the impeller passage 86 to the outer side of the impeller 70 in the radial direction does not collide against the upper end portion P2. This structure can thus prevent air from flowing into a gap GA2 in the radial direction between the impeller housing body 82 and the radially outer end portion of the shroud annular portion 72 a. The blower 1 according to this embodiment can thus have high blowing efficiency.

The gap GA2 is smaller than a gap GA3 between the shroud-facing surface 82 b and the outer surface of the shroud 72. The shroud-facing surface 82 b is described below. This structure can prevent air flowing through the connection passage 84 from flowing into the gap GA3 through the gap GA2.

The upper end portion P2 of the curved surface 82 a is located lower than the radially outer end of the upper surface of the shroud annular portion 72 a. Thus, air discharged from the impeller passage 86 to the radially outer side of the impeller 70 is more likely to flow over the curved surface 82 a. This structure can thus reduce the loss of air caused when the air flows from the impeller passage 86 to the air-discharge passage 87 through the connection passage 84. Thus, the blower 1 according to this embodiment can have high blowing efficiency.

The shroud-facing surface 82 b is a surface facing the shroud 72 of the impeller 70. The shroud-facing surface 82 b has a contour following the outer surface of the shroud 72. This structure facilitates reduction of the width of the gap GA3 between the shroud-facing surface 82 b and the outer surface of the shroud 72.

If, for example, the gap GA3 has an excessively large width, the pressure inside the gap GA3 would be low, and this structure would allow air to flow into the gap GA3, so that the loss of air would be more likely to increase. On the other hand, in this embodiment, the gap GA3 can have a small width. This structure can prevent air from flowing into the gap GA3, and thus can reduce the loss of air. The gap GA3 has, for example, a substantially uniform width.

An inlet guide 81 protrudes inward in the radial direction from the inner edge of the upper end portion of the impeller housing body 82. The inlet guide 81 is, for example, annular. An upper opening of the inlet guide 81 serves as an inlet port 80 a. The radially inner surface of the inlet guide 81 is a curved surface located further to the radially outer side from the lower side toward the upper side.

The inlet guide 81 is located higher than the shroud cylinder portion 72 b. A gap GA1 in the axial direction between the inlet guide 81 and the shroud cylinder portion 72 b is smaller than the gap GA3. This structure can thus prevent air flowing from the inlet port 80 a into the impeller 70 from flowing into the gap GA3 through the gap GA1.

The position of the radially inner end portion of the inlet guide 81 in the radial direction is located at substantially the same as the position of the radially inner end portion of the shroud cylinder portion 72 b in the radial direction. Thus, air that has flowed into the impeller 70 along the inlet guide 81 is more likely to flow along the shroud cylinder portion 72 b. This structure can thus reduce the loss of air taken into the impeller 70.

When the impeller 70 has its position shifted inward in the radial direction due to, for example, vibrations at a rotation, air flowing from the inlet port 80 a along the inlet guide 81 may collide against the upper end portion of the shroud cylinder portion 72 b and may be separated. This may increase the loss of air.

In this embodiment, to address this situation, the inner surface of the shroud cylinder portion 72 b has the curved surface 72 d at the upper end portion, as described above. Thus, even when the impeller 70 has its position shifted in the radial direction, air is more likely to flow downward along the curved surface 72 d. This structure can thus reduce the loss of air.

As illustrated in FIG. 1, when the impeller 70 is rotated by the motor 10, air flows into the impeller 70 through the inlet port 80 a. Air that has flowed into the impeller 70 is discharged to the radially outer side from the impeller passage 86. Air discharged from the impeller passage 86 flows from the upper side toward the lower side through the connection passage 84 and the air-discharge passage 87 and is discharged downward from the outlet port 88. In this manner, the blower 1 transports air.

This embodiment can also employ the following structure.

In this embodiment, the impeller 70 may be a single component. In this embodiment, the bearing holding member 60 may be constituted of two holding member pieces 60 a or four or more holding member pieces 60 a.

The holding member pieces 60 a may have different shapes. Multiple outer protrusions 63 may be arranged in the circumferential direction.

FIG. 7 and FIG. 8 do not illustrate a passage member 161, a bearing holding member 160, an impeller 70, and an impeller housing 80. Components the same as those in the first embodiment may be appropriately denoted with the same reference signs and not described.

As illustrated in FIG. 6, the blower 2 includes a motor 110, a bearing holding member 160, an impeller 70, a passage member 161, multiple stator blades 167, and an impeller housing 80.

The motor 110 includes a housing 120, a rotor 30, a stator 140, a lower bearing 52 a, an upper bearing 52 b, and a connector 90. The rotor 30 includes a shaft 31. The housing 120 includes a circumferential wall 121, a lower lid portion 22, and a lower bearing holder 22 b.

As illustrated in FIG. 7, the circumferential wall 121 has multiple through holes 121 a and multiple cutouts 121 b. As illustrated in FIG. 6, the upper end portion of the through hole 121 a is located lower than a stator core 141, described below. Other portions of the through hole 121 a are the same as those of the through hole 21 a according to the first embodiment.

As illustrated in FIG. 7, the cutouts 121 b are cut portions of the circumferential wall 121 that are cut from the upper end portion toward the lower side. Specifically, the cutouts 121 b extend through the circumferential wall 121 in the radial direction to open to the upper side. For example, six cutouts 121 b are equidistantly arranged in the circumferential direction. For example, the cutouts 121 b are rectangular extending in the axial direction when viewed in the radial direction.

As illustrated in FIG. 8, the stator 140 includes a stator core 141. The stator core 141 includes a core back portion 41 a, teeth 41 b, and core protrusions 141 c. The core protrusions 141 c protrude from the outer circumferential surface of the core back portion 41 a to the radially outer side. For example, six core protrusions 141 c are arranged in the circumferential direction.

Each core protrusion 141 c is fitted to the corresponding one of the cutouts 121 b. The radially outer surface of the core protrusion 141 c is flush with the outer circumferential surface of the housing 120. The radially outer surface of each core protrusion 141 c is exposed to the outside of the housing 120. In this embodiment, the multiple cutouts 121 b are equidistantly arranged in the circumferential direction. Thus, on the outer circumferential surface of the motor 110, the outer circumferential surfaces of the core protrusions 141 c and the outer circumferential surface of the housing 120 are alternately arranged in the circumferential direction.

As illustrated in FIG. 6, each core protrusion 141 c has its radially outer surface facing the air-discharge passage 87. Thus, in this embodiment, the stator core 141 can be cooled by air flowing through the air-discharge passage 87.

Each core protrusion 141 c has its lower end portion in contact with the upper edge of the corresponding one of the cutouts 121 b. Thus, the stator core 141 has its position of fixed in the axial direction.

Each stator blade 167 includes a stator blade lower portion 167 a and a stator blade upper portion 167 b. The stator blade lower portion 167 a and the stator blade upper portion 167 b are, for example, separate members. The other structure of the stator blade lower portion 167 a is similar to the structure of the stator blade lower portion 67 a according to the first embodiment. The other structure of the stator blade upper portion 167 b is similar to the structure of the stator blade upper portion 67 b according to the first embodiment.

The bearing holding member 160 is similar to the bearing holding member 60 according to the first embodiment except having its outer circumferential surface to which each stator blade upper portion 167 b is fixed. Each stator blade upper portion 167 b is fixed to the outer surface of the bearing holding member 160. Each holding member piece and the corresponding one of the stator blade upper portions 167 b are formed as, for example, a single component. In this embodiment, the bearing holding member 160 functions as a diffuser including the stator blade upper portions 167 b serving as stator blades.

The number of the holding member pieces constituting the bearing holding member 160 is a divisor of the number of the stator blade upper portions 167 b. Specifically, the number of the holding member pieces is a divisor of the number of the stator blades 167. Thus, the holding member pieces can have the same number of the stator blade upper portions 167 b. In the structure where the bearing holding member 160 includes the stator blade upper portions 167 b, the holding member pieces can have the same shape. This structure facilitates manufacturing of the holding member pieces.

For example, when the number of the stator blade upper portions 167 b is 15 and the number of the holding member pieces constituting the bearing holding member 160 is 3, the number of the stator blade upper portions 167 b included in each holding member piece is 5.

In this embodiment, the passage member 161 is a single component. Each stator blade lower portion 167 a is fixed to the inner circumferential surface of the passage member 161. The passage member 161 and the stator blade lower portions 167 a are formed as, for example, a single component. The other structure of the passage member 161 is similar to the structure of the passage member 61 according to the first embodiment. The other structure of the blower 2 is similar to the structure of the blower 1 according to the first embodiment.

In this embodiment, the number of the cutouts 121 b is not limited to a particular one, and may be five or smaller or seven or larger. In this embodiment, instead of the cutouts 121 b, through holes that extend through the circumferential wall 121 in the radial direction may be formed.

Alternatively, for example, the entirety of the stator blades 167 each constituted of the stator blade lower portion 167 a and the stator blade upper portion 167 b may be integrated with the corresponding one of the holding member pieces constituting the bearing holding member 160.

FIG. 9 is a sectional view of a blower 3 according to a third embodiment. The blower 3 includes a motor 210, an impeller 270, an impeller housing 280, a motor housing 260, a passage member 261, and multiple stator blades 267. The motor housing 260 is a component corresponding to the bearing holding member 60 according to the first embodiment. Here, an upper bearing 252 b may be held by a component other than the motor housing 260.

The motor 210 includes a shaft 231 vertically extending along the center axis J. The motor 210 includes a rotor 230, a stator 240, a lower bearing 252 a, and the upper bearing 252 b. The rotor 230 is disposed on the radially inner side of the stator 240 and connected to the shaft 231. The shaft 231 is supported by the stator 240 so as to be rotatable around the center axis J with the lower bearing 252 a and the upper bearing 252 b interposed therebetween.

The impeller 270 is connected to the shaft 231 and rotates integrally with the shaft 231. The impeller housing 280 is disposed on the upper side or the radially outer side of the impeller 270. In the blower 3, the impeller housing 280 surrounds the upper side and the radially outer side of the impeller 270, and includes, at a center portion, an inlet port 280 a extending through in the axial direction.

The motor housing 260 is disposed on the radially outer side of the motor 210. The motor housing 260 is a substantially cylindrical closed-top component that is open to the lower side. The passage member 261 is disposed on the radially outer side of the motor housing 260 with a gap interposed therebetween. Specifically, the radially outer surface of the motor housing 260 and the radially inner surface of the passage member 261 are disposed while having a gap interposed therebetween in the radial direction. Thus, the gap interposed between the motor housing 260 and the passage member 261 serves as a passage.

The multiple stator blades 267 are arranged in the circumferential direction in the gap between the motor housing 260 and the passage member 261. The multiple stator blades 267 are located to the radially outer side of the radially outer end of the impeller 270. The axially upper ends of the multiple stator blades 267 are located to the axially lower side of the axially lower end of the impeller 270. At least one of the multiple stator blades 267 is constituted of multiple sections. Specifically, at least one of the stator blades 267 includes a first stator blade 268 and a second stator blade 269. The first stator blade 268 is disposed on either one of the motor housing 260 and the passage member 261. The second stator blade 269 is disposed on the other one of the motor housing 260 and the passage member 261. In this embodiment, the motor housing 260 includes the first stator blade 268 on its outer surface, and the passage member 261 includes the second stator blade 269 on its inner surface.

The first stator blade 268 and the second stator blade 269 are connected together in the radial direction or in the axial direction. This structure can firmly fix the first stator blade 268 and the second stator blade 269 to each other. When the first stator blade 268 disposed on the motor housing 260 and the second stator blade 269 disposed on the passage member 261 are fixed together, the radially outer surface of the motor housing 260 and the radially inner surface of the passage member 261 can be arranged with high concentricity. This structure can further uniform the radial dimension of the passage in the circumferential direction, so that the blower 3 can have high blowing efficiency.

FIG. 10 is a perspective view of the motor housing 260 according to the third embodiment. FIG. 11 is a bottom view of the passage member 261 according to the third embodiment. With reference to FIG. 9 to FIG. 11, each first stator blade 268 and each second stator blade 269 respectively include a first connecting portion 268A and a second connecting portion 269A. The first connecting portion 268A is included in each first stator blade 268 and comes into contact with part of the corresponding second stator blade 269. The second connecting portion 269A is included in each second stator blade 269 and comes into contact with part of the corresponding first stator blade. At least part of each first connecting portion 268A and at least part of the corresponding second connecting portion 269A are in contact with each other in the axial direction. This structure can fix the positions of each first stator blade 268 and the corresponding second stator blade 269 in the axial direction when the first stator blade 268 and the second stator blade 269 are coupled together.

In addition, at least part of each first connecting portion 268A and at least part of the corresponding second connecting portion 269A are in contact with each other in the circumferential direction. This structure can fix the positions of each first stator blade 268 and the corresponding second stator blade 269 in the circumferential direction when the first stator blade 268 and the second stator blade 269 are coupled together. Specifically, each first connecting portion 268A and the corresponding second connecting portion 269A are in contact with each other in the axial direction and the circumferential direction, and have their positions determined in the axial direction and the circumferential direction. Each first stator blade 268 and the corresponding second stator blade 269, having their positions determined in the axial direction and the circumferential direction, can be fixed to each other without being displaced with respect to each other.

Each first connecting portion 268A includes a protrusion 268B extending in the axial direction or the radial direction. Each second connecting portion 269A includes a recess 269B, recessed in the axial direction or the radial direction. In this embodiment, the protrusion 268B extends to radially lower side from the surface of the first stator blade 268 facing the axially lower side at the lower portion of the first stator blade 268. The protrusion 268B and the surface of the first stator blade 268 facing the axially lower side at the lower portion of the first stator blade 268 constitute the first connecting portion 268A. The recess 269B in the second stator blade 269 is recessed from the radially inner side to the radially outer side. The recess 269B and the upper surface of the second stator blade 269 constitute the second connecting portion 269A.

A circumferential width W1 of at least part of the protrusion 268B is smaller than a circumferential width W2 of each stator blade 267. To assemble the blower 3, the motor housing 260 including the first stator blades 268 is moved downward in the axial direction. Each protrusion 268B is thus inserted into the corresponding recess 269B. Thus, each first stator blade 268 and the corresponding second stator blade 269 have their positions concurrently restricted in the axial direction and the circumferential direction. This simple structure and assembly process enable firm fixing between each first stator blade 268 and the corresponding second stator blade 269, and facilitate the productivity.

In this embodiment, the first stator blades 268 are located higher than the second stator blades 269 in the axial direction. Each first stator blade 268 has a first side surface 268C, facing rearward in an impeller rotation direction R. Each second stator blade 269 has a second side surface 269C, facing rearward in the impeller rotation direction R. The first side surface 268C and the second side surface 269C are smoothly connected to each other. Specifically, when each first stator blade 268 and the corresponding second stator blade 269 are coupled together, the first side surface 268C and the second side surface 269C form a side surface of one of the stator blades 267 facing rearward in the impeller rotation direction R. Thus, air flowing through the passage is smoothly guided to the axially lower side along the first side surface 268C and the second side surface 269C, so that the blower 3 has a higher blowing efficiency. The surface of each stator blade 267 facing forward in the impeller rotation direction R is also constituted of the surface of the corresponding first stator blade 268 facing forward in the impeller rotation direction R and the surface of the corresponding second stator blade 269 facing forward in the impeller rotation direction R. Thus, the blower 3 has a higher blowing efficiency.

As illustrated in FIG. 10, an upper portion of each first side surface 268C is curved forward in the rotation direction R from the upper side to the lower side in the axial direction. More specifically, an upper portion of each first side surface 268C is a surface smoothly curved forward in the impeller rotation direction R and protruding toward the axially upper side. In this structure, air discharged from the impeller 270 to the radially outer side is smoothly guided to the axially lower side along the curved surface at the upper portion of the first side surface 268C while retaining the component circling in the circumferential direction to the front side in the impeller rotation direction R, and then flows to the axially lower side. Thus, the blower 3 has high blowing efficiency.

With reference to FIG. 9, in a gap in the axial-direction area A in which each stator blade 267 is disposed, a gap d1 in the radial direction at the upper end of the axial-direction area A is wider than a gap d2 in the radial direction at the lower end of the axial-direction area A. Specifically, in the axial-direction area A in which the stator blades 267 are disposed, the gap in the radial direction in the passage at the upper end is wider than the gap in the radial direction in the passage at the lower end. Thus, the passage has a small sectional area in the area where the stator blades 267 are disposed, so that the air flowing through the passage has a high static pressure. This structure can thus reduce an occurrence of a turbulence in the axial-direction area A. Thus, air flows through the passage more smoothly, and the blower 3 has high blowing efficiency.

The gap d2 in the radial direction at the lower end of the axial-direction area A is narrower than a gap d3 in the radial direction at a portion below the axial-direction area A in the axial direction, between the outer surface of the motor housing 260 and the inner surface of the passage member 261. Specifically, the gap d3 in the radial direction in the passage at a portion below the axial-direction area A in the axial direction is wider than the gap in the radial direction in the passage at the lower portion of the axial-direction area A. Thus, air having its static pressure raised in the axial-direction area A smoothly flows to the axially lower side, since the resistance in the passage gradually decreases as the passage has its sectional area increased at a portion below the axial-direction area A in the axial direction. Thus, the blower 3 has high blowing efficiency.

With reference to FIG. 11, the multiple stator blades 267, each having the first stator blade 268 and the second stator blade 269, are irregularly arranged in the circumferential direction. Specifically, in FIG. 11, at least one of gaps in the circumferential direction between adjacent two of the multiple second stator blade 269 differs from the other gaps in the circumferential direction. Similarly, gaps in the circumferential direction between adjacent two of the multiple first stator blades 268 are determined in the same manner as those of the multiple second stator blades 269. Thus, the motor housing 260 and the passage member 261 have their positions fixed in the circumferential direction.

In the third embodiment, the first stator blades 268 are located higher than the second stator blades 269. However, the first stator blades 268 may be located lower than the second stator blades 269. The first stator blades 268 may be disposed on the passage member 261, instead of the motor housing 260. The protrusions 268B may be formed on the second stator blades 269. The recesses 269B may be formed on the first stator blades 268.

In the third embodiment, each first connecting portions 268A and each second connecting portions 269A are respectively constituted of the flat surface substantially perpendicular to the axial direction and the protrusion 268B that protrudes in the axial direction from the flat surface, and constituted of the flat surface and the recess 269B recessed from the flat surface in the axial direction. However, the first connecting portions 268A and the second connecting portions 269A may have other shapes. For example, the undersurface of each first connecting portion 268A may be a slope that is inclined with respect to the axial direction.

As an example of another structure, the upper end portion of the second connecting portion 269A may be exposed to the upper side in the axial direction when each stator blade 267 is viewed from the axially upper side. Specifically, in the third embodiment, the upper end portion of the second connecting portion 269A is in contact with the first connecting portion 268A in the axial direction. Thus, when each stator blade 267 is viewed from the axially upper side, the second connecting portion 269A is not exposed to the upper side in the axial direction, but may be exposed to the upper side in the axial direction. Alternatively, when viewed from the axially lower side, the lower end portion of the first connecting portion 268A may be exposed to the axially lower side.

FIG. 12 is a side view of stator blades 367 according to a fourth embodiment. For convenience purposes, a passage member disposed on the radially outer side is not illustrated. Multiple stator blades 367 are arranged in the circumferential direction. At least one of the multiple stator blades 367 is constituted of multiple sections. Specifically, at least one of the stator blades 367 includes a first stator blade 368 and a second stator blade 369. The first stator blade 368 is disposed on either one of a motor housing 360 and the passage member. The second stator blade 369 is disposed on the other one of the motor housing 360 and the passage member.

The first stator blade 368 and the second stator blade 369 respectively include a first connecting portion 368A and a second connecting portion 369A. The first connecting portion 368A and the second connecting portion 369A respectively include a first stepped portion 368E and a second stepped portion 369E extending in the axial direction. The surfaces of the first stepped portion 368E and the second stepped portion 369E facing each other in the axial direction or the circumferential direction are in contact with each other. In the fourth embodiment, the surface of the first stepped portion 368E facing in the axial direction, that is, the undersurface of the first stepped portion 368E is in contact with the surface of the second stepped portion 369E facing in the axial direction, that is, the upper surface of the second stepped portion 369E. In addition, the surface of the first stepped portion 368E facing in the circumferential direction, that is, a side surface of the first stepped portion 368E, is in contact with the surface of the second stepped portion 369E facing in the circumferential direction, that is, a side surface of the second stepped portion 369E. Thus, the first stator blade 368 and the second stator blade 369 can have their positions fixed in both the axial direction and the circumferential direction. In addition, compared to the structure according to the third embodiment, the structure of the first connecting portion 368A and the second connecting portion 369A can be simplified. Thus, the blower can be assembled with lower costs and simple processes. The surfaces of the first stepped portion 368A and the second stepped portion 369A facing each other in either one of the axial direction and the circumferential direction only have to be in contact with each other, and the surfaces facing each other in both the axial direction and the circumferential direction do not have to be in contact with each other.

The first stator blade 368 includes a first side surface 368C facing rearward in the impeller rotation direction R. The second stator blade 369 includes a second side surface 369C facing rearward in the impeller rotation direction R. In the circumferential direction, a lower end portion 368D of the first side surface is located further to the rear side, in the impeller rotation direction R, of the upper end portion 369D of the second side surface. This structure reduces the resistance that the air flowing near the first side surface receives, compared to the case where, in the circumferential direction, the lower end portion 368D of the first side surface is located further to the front side, in the impeller rotation direction R, of the upper end portion 369D of the second side surface. In an assembly process, even when the upper end portion 369D of the second side surface has its position slightly shifted to the rear side in the impeller rotation direction R, the upper end portion 369D of the second side surface is prevented from protruding beyond the first side surface 368C to the rear side in the impeller rotation direction R. Desirably, the lower end portion 368D of the first side surface and the upper end portion 369D of the second side surface are located at the same position in the impeller rotation direction R for enhancing the blowing efficiency.

FIG. 13 is a side view of a stator blade 467 according to a fifth embodiment. For convenience purposes, FIG. 13 does not include the illustration of a passage member disposed on the radially outer side of the stator blade 467. A blower according to the fifth embodiment has a structure similar to the structure according to the third embodiment except for the stator blade 467.

The stator blade 467 is disposed on either one of the motor housing and the passage member. The stator blade 467 has a recess 468F at an axially lower end portion that is recessed upward in the axial direction. The stator blade 467 also has a connecting portion 469F disposed on the other one of the motor housing and the passage member. In this embodiment, the stator blade 467 is integrated with the passage member. The connecting portion 469F is integrated with the motor housing. The connecting portion 469F is engaged with at least part of the recess 468F. This structure involving low costs and having high productivity enables firm fixing between the stator blade 467 and the connecting portion 469F.

The stator blade 467 according to the fifth embodiment is different from the stator blade 267 according to the third embodiment or the stator blade 367 according to the fourth embodiment in terms that the connecting portion 469F does not constitute a side surface of the stator blade 467. Specifically, in the stator blade 467, the side surfaces of the stator blade 467 are formed by only the stator blade 467 integrated with either one of the motor housing and the passage member. The connecting portion 469F constitutes part of the undersurface of the stator blade 467 and is not exposed to other surfaces. In this embodiment, the stator blade 467 is located higher than the connecting portion 469F. However, the stator blade may be located lower than the connecting portion and may include a recess recessed to the lower side in the upper surface of the stator blade.

FIG. 14 is a side view of a stator blade 567 according to a sixth embodiment. For convenience purposes, FIG. 14 does not include the illustration of a passage member disposed to the radially outer side of the stator blade 567. A blower according to the sixth embodiment has a structure similar to the structure according to the third embodiment except for the stator blade 567.

The stator blade 567 is disposed on either one of the motor housing and the passage member. The state blade 567 includes a recess 568F in the surface facing forward in the impeller rotation direction R. The recess 568F is recessed to the rear side in the impeller rotation direction R. The stator blade 567 also includes a connecting portion 569F on the other one of the motor housing and the passage member. The connecting portion 569F is engaged with at least part of the recess 568F. In this embodiment, the stator blade 567 is integrated with the motor housing, and the connecting portion 569F is integrated with the passage member. This structure involving low costs and having high productivity enables firm fixing between the stator blade 567 and the connecting portion 569F.

The stator blade 567 is different from the stator blade 267 according to the third embodiment or the stator blade 367 according to the fourth embodiment in terms that the connecting portion 569F does not constitute a side surface of the stator blade 567. The connecting portion 569F constitutes part of a surface of the stator blade 567 facing forward in the impeller rotation direction R, and is not exposed to other surfaces. The recess 568F may be formed in the surface facing rearward in the impeller rotation direction R and engaged with the connecting portion 569F.

A vacuum cleaner 100 illustrated in FIG. 15 includes a blower according to the present disclosure. In the blower installed in the vacuum cleaner, the first stator blade and the second stator blade can be firmly fixed together.

The blower according to each of the first to sixth embodiments may be used in any device. The blower according to each of the first to sixth embodiments may be used in, for example, a vacuum cleaner or a drier.

Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

While preferred embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims. 

1-14. (canceled) 15: A blower, comprising: a motor that includes a shaft disposed along a center axis extending vertically; an impeller that is connected to the shaft and rotates integrally with the shaft; an impeller housing that is disposed on an upper side of the impeller or a radially outer side of the impeller; a motor housing that is disposed on a radially outer side of the motor; a passage member that is disposed on a radially outer side of the motor housing with a gap interposed therebetween; and a plurality of stator blades that are arranged in a circumferential direction in the gap between the motor housing and the passage member, wherein at least one of the stator blades includes a first stator blade disposed on either one of the motor housing and the passage member, and a second stator blade disposed on the other one of the motor housing and the passage member, and wherein the first stator blade and the second stator blade are coupled together in a radial direction or an axial direction. 16: The blower according to claim 15, wherein the first stator blade and the second stator blade respectively have a first connecting portion and a second connecting portion, and wherein at least part of the first connecting portion and at least part of the second connecting portion are in contact with each other in the axial direction. 17: The blower according to claim 15, wherein the first stator blade and the second stator blade respectively have a first connecting portion and a second connecting portion, and wherein at least part of the first connecting portion and at least part of the second connecting portion are in contact with each other in the circumferential direction. 18: The blower according to claim 16, wherein the first connecting portion includes a protrusion extending in the axial direction or the radial direction, wherein the second connecting portion includes a recess recessed in the axial direction or the radial direction, wherein a circumferential width of at least part of the protrusion is smaller than a circumferential width of the stator blade, and wherein the protrusion is inserted into the recess. 19: The blower according to claim 16, wherein the first connecting portion and the second connecting portion respectively have a first stepped portion and a second stepped portion extending in the axial direction, and surfaces of the first stepped portion and the second stepped portion facing each other in the axial direction, or surfaces of the first stepped portion and the second stepped portion facing each other in the circumferential direction are in contact with each other. 20: The blower according to claim 15, wherein the first stator blade is located to an axially upper side of the second stator blade, wherein the first stator blade has a first side surface facing to a rear side in a rotation direction of the impeller, wherein the second stator blade has a second side surface facing to the rear side in the rotation direction of the impeller, and wherein the first side surface and the second side surface are smoothly connected together. 21: The blower according to claim 20, wherein, in the circumferential direction, a lower end portion of the first side surface is located to a rear side of an upper end portion of the second side surface in the rotation direction of the impeller. 22: The blower according to claim 15, wherein the stator blade including the first stator blade and the second stator blade includes a plurality of stator blades arranged irregularly in the circumferential direction. 23: The blower according to claim 20, wherein an upper portion of the first side surface is curved to a front side in the rotation direction from the axially upper side toward an axially lower side. 24: The blower according to claim 15, wherein, in the gap of an axial-direction area in which the stator blades are disposed, a gap in the radial direction at an upper end of the axial-direction area is wider than a gap in the radial direction at a lower end of the axial-direction area. 25: The blower according to claim 24, wherein the gap in the radial direction at the lower end of the axial-direction area is narrower than a gap in the radial direction between an outer surface of the motor housing at a portion below the axial-direction area in the axial direction and an inner surface of the passage member. 26: A blower, comprising: a motor that includes a shaft disposed along a center axis extending vertically; an impeller that is connected to the shaft and rotates integrally with the shaft; an impeller housing that is disposed on an upper side of the impeller or a radially outer side of the impeller; a motor housing that is disposed on a radially outer side of the motor; a passage member that is disposed on a radially outer side of the motor housing with a gap interposed therebetween; and a plurality of stator blades that are arranged in a circumferential direction in the gap between the motor housing and the passage member, wherein the stator blades are disposed on either one of the motor housing and the passage member, and each have a recess recessed to an upper side in an axial direction at an axially lower end portion, wherein a connecting portion is disposed on the other one of the motor housing and the passage member, and wherein the connecting portion is engaged with at least one of the recesses. 27: A blower, comprising: a motor that includes a shaft disposed along a center axis extending vertically; an impeller that is connected to the shaft and rotates integrally with the shaft; an impeller housing that is disposed on an upper side of the impeller or a radially outer side of the impeller; a motor housing that is disposed on a radially outer side of the motor; a passage member that is disposed on a radially outer side of the motor housing with a gap interposed therebetween; and a plurality of stator blades that are arranged in a circumferential direction in the gap between the motor housing and the passage member, wherein the stator blades are disposed on either one of the motor housing and the passage member, and each have a recess recessed in the circumferential direction in a surface of the stator blade facing to a front side in a rotation direction of the impeller, wherein a connecting portion is disposed on the other one of the motor housing and the passage member, and wherein the connecting portion is engaged with at least one of the recesses. 28: A vacuum cleaner, comprising the blower according to claim
 15. 